Tofani S, Ossola P, d'Amore G, Gandhi O P
Laboratorio di Sanità Pubblica, Ivrea, Italy.
Health Phys. 1995 Jan;68(1):71-9. doi: 10.1097/00004032-199501000-00009.
We have used the impedance method to calculate the induced electric (E) fields and current densities (J) for the spatially varying vector magnetic fields due to a hair dryer. In this method, applicable for low-frequency exposures where the quasi-static approximation may be made, the biological body or the exposed parts thereof are represented by a three-dimensional (3-D) network of impedances whose individual values are obtained from the electrical properties sigma, epsilon r for the various tissues. We have measured the 3-D variations of the 50-Hz magnetic fields from a typical hair dryer and found that the various components correlate well with those for a helical coil. The non-uniform magnetic fields thus obtained are used to calculate the induced E and J with a resolution of 1.31 cm for the model of the head and neck. The induced E values are compared with the fields endogenous to the body and the minimum detectable E-field limits based on the cellular thermal noise model proposed by Weaver and Astumian (1990, 1992).
我们已使用阻抗方法来计算由于吹风机产生的空间变化矢量磁场的感应电场（E）和电流密度（J）。在这种适用于可进行准静态近似的低频暴露的方法中，生物体或其暴露部分由一个三维（3-D）阻抗网络表示，其各个值从各种组织的电特性电导率（sigma）、相对介电常数（epsilon r）获得。我们测量了一台典型吹风机50赫兹磁场的三维变化，发现各个分量与螺旋线圈的分量相关性良好。由此获得的非均匀磁场用于以1.31厘米的分辨率计算头部和颈部模型的感应E和J。将感应E值与身体内源性场以及基于韦弗和阿斯图米安（1990年、1992年）提出的细胞热噪声模型的最小可检测电场极限进行比较。
